I added some more circuity to the junkyard welder. now I can switch it from welder to dual alternator. Or if my primary alternator craps out, I can run this a main alternator. So with both alternators running, I'll have up to 220A on tap.

Thats cool! If you add anything else you'll need to start thinking of replacing that little Geo motor or electric clutches. BTW what is the OCV with the alternator full fielded at 1800RPM. If its above 20VDC you maybe able to run a MIG spool gun with it.

the OCV changes with rpm. at 1800 its probably about 40-50 volts, but I need to crank the engine up to about 2500 rpm to strike an arc w/ an 1/8" rod. so the voltage is up at 60-70 volts, which probably isnt all that safe when you are standing in a foot of snow next to what you are welding. The next add-on will be to tie it into the computer I have in the dash. I can program the computer to PWM the current to field and regulate the OCV. So I can crank up the amps for welding w/out electrocuting myself in the process.

The biggest thing with winches is the battery adding another alt isn:t really going to help as much as using a dual purpose battery. Another problem is your stock alt output at idle to around 1400rpm isn't all that great so adding two and not increasing rpm will net you nothing but increased windage. I would buy another battery and isolate it for winch use or buy a Optima blue with the light grey case and not worry about it.

For starters, you absolutely need a deep cycle battery. Winching will kill a regular battery pretty damn quick. You can go with an optima, or just buy a cheapo marine battery at Walmart like i did. Unless you plan on a lot of roll overs, I don't really think the optima offers much more than the additional safety of being a sealed battery. If you are worried that your battery wont keep pace with the winch, pat is correct about the dual battery setup (both deep cycle). At peak demand, a winch can draw 500-600 amps. You are banking on the reserve in the battery top get you through short bursts of winching, not the alternator output. you would probably need about 4 high capacity alternators to provide enough juice to meet the peak demand of the winch.

I always buy the Napa Performance Select 84 34/78 Group size (top and side posts). Under $100 and its 800CCA. Plus its a 24 month free replacement warranty and 84 month prorated. I Have them in three vehicles with the oldest one still running strong in the Willys with 8 yrs of offroad winching and starting duty.